diff --git a/allocate_laptop.py b/allocate_laptop.py
new file mode 100644
index 00000000..3a842d9d
--- /dev/null
+++ b/allocate_laptop.py
@@ -0,0 +1,91 @@
+from dataclasses import dataclass
+from enum import Enum
+from typing import List, Dict, Tuple, Optional
+
+class OperatingSystem(Enum):
+    MACOS = "macOS"
+    ARCH = "Arch Linux"
+    UBUNTU = "Ubuntu"
+
+@dataclass(frozen=True)
+class Person:
+    name: str
+    age: int
+    # Sorted in order of preference, most preferred is first.
+    preferred_operating_systems: List[OperatingSystem]
+
+
+@dataclass(frozen=True)
+class Laptop:
+    id: int
+    manufacturer: str
+    model: str
+    screen_size_in_inches: float
+    operating_system: OperatingSystem
+
+def norm_os_values(value: str) -> OperatingSystem:
+    value = value.strip().lower()
+    if value == "ubuntu":
+        return OperatingSystem.UBUNTU
+    if value == "arch linux":
+        return OperatingSystem.ARCH
+    if value == "macos":
+        return OperatingSystem.MACOS
+    raise ValueError(f"Unknown OS: {value}")
+
+
+people = [
+    Person(name="Imran", age=22, preferred_operating_systems=[norm_os_values("Ubuntu"), norm_os_values("Arch Linux")]),
+    Person(name="Eliza", age=34, preferred_operating_systems=[norm_os_values("Arch Linux"), norm_os_values("macOS"), norm_os_values("Ubuntu")]),
+    Person(name="Ira", age=21, preferred_operating_systems=[norm_os_values("Ubuntu"), norm_os_values("Arch Linux")]),
+    Person(name="Anna", age=34, preferred_operating_systems=[norm_os_values("Ubuntu"), norm_os_values("macOS")]),
+    Person(name="Nahimn", age=42, preferred_operating_systems=[norm_os_values("Ubuntu"), norm_os_values("Arch Linux")])
+]
+
+laptops = [
+    Laptop(id=1, manufacturer="Dell", model="XPS", screen_size_in_inches=13, operating_system=norm_os_values("Arch Linux")),
+    Laptop(id=2, manufacturer="Dell", model="XPS", screen_size_in_inches=15, operating_system=norm_os_values("Ubuntu")),
+    Laptop(id=3, manufacturer="Dell", model="XPS", screen_size_in_inches=15, operating_system=norm_os_values("ubuntu")),
+    Laptop(id=4, manufacturer="Apple", model="macBook", screen_size_in_inches=13, operating_system=norm_os_values("macOS")),
+]
+
+
+def allocate_laptops(people: List[Person], laptops: List[Laptop]) -> Dict[Tuple[str, int], int]:
+    sadness_table: Dict[Tuple[str, int], int] = {}
+    for person in people:
+        for laptop in laptops:
+            if laptop.operating_system in person.preferred_operating_systems:
+                index = person.preferred_operating_systems.index(laptop.operating_system)
+                sadness = index
+            else:
+                sadness = 100
+            sadness_table[(person.name, laptop.id)] = sadness
+    return sadness_table
+
+
+sadness_table = allocate_laptops(people, laptops)
+
+allocation_list: List[Tuple[str, Optional[int], int]] = []
+allocated_laptops: set[int] = set()
+allocated_persons: set[str] = set()
+total_happiness: int = 0
+
+for (person_name, laptop_id), sadness in sorted(sadness_table.items(), key=lambda value: value[1]):
+    if laptop_id in allocated_laptops:
+        continue
+    if person_name in allocated_persons:
+        continue
+    allocation_list.append((person_name, laptop_id, sadness))
+    allocated_laptops.add(laptop_id)
+    allocated_persons.add(person_name)
+    total_happiness += sadness
+    print(f"{person_name} got laptop {laptop_id}")
+
+    
+for person in people:
+    if person.name not in allocated_persons:
+        print(f"{person.name} did not get laptop")
+print(f"Total happiness: {total_happiness}")
+
+print(allocation_list)
+